12results about How to "Adjustable molecular weight" patented technology

The invention discloses a high-frequency low-dielectric-loss benzocyclobutene resin and a preparation method and application thereof. 1, 3-diolefin, a benzocyclobutene group, a vinyl compound, an initiator and an organic solvent are subjected to a polymerization reaction at-5 DEG C to-78 DEG C and then treated to obtain the high-frequency low-dielectric-loss benzocyclobutene resin. The high-frequency low-dielectric-loss benzocyclobutene resin prepared by the preparation method disclosed by the invention has excellent thermal stability, mechanical property and dielectric property after being cured at high temperature. Under the frequency of 10 GHz, the dielectric constant (Dk) of the cured resin is 2.35-2.60, the dielectric loss (Df) of the cured resin is 0.0004-0.0007, the T5% thermal decomposition temperature of the cured resin is 442-465 DEG C, and the thermal expansion coefficient of the cured resin is 32-88 ppm / DEG C at 50 DEG C. Therefore, the material can be used as a high-temperature-resistant dielectric material, a high-performance composite material, an electronic packaging material, an aeronautical material and the like; the method is applied to a 5G / 6G high-frequency PCB, interlayer packaging of a chip and the like.

The invention discloses a high-frequency low dielectric loss benzocyclobutene resin and its preparation method and application. The 1,3-position diene, benzocyclobutene group, vinyl compound, initiator and organic solvent are polymerized under the conditions of 5°C to 78°C and then treated to obtain a high-frequency low dielectric loss benzocyclobutene resin. The high-frequency low dielectric loss benzocyclobutene resin prepared by the present invention has excellent thermal stability, mechanical properties and dielectric properties after high-temperature curing. At a frequency of 10 GHz, its dielectric constant (Dk) is 2.35-2.60, dielectric loss (Df) is 0.0004-0.0007, T 5％ The thermal decomposition temperature is 442‑465°C, and the thermal expansion coefficient of the cured resin is 32‑88ppm / °C@50°C. Therefore, it can be used as high-temperature resistant dielectric materials, high-performance composite materials, electronic packaging materials, and aviation materials; it can be used in 5G / 6G high-frequency PCB boards and interlayer packaging of chips, etc.

The application provides a high-refraction cycloolefin copolymer and a preparation method thereof, and has a structure of formula I. The cycloolefin copolymer can obtain a cycloolefin copolymer resin with high thermal stability due to high steric hindrance of the cycloolefin monomer. The refractive index of the cycloolefin copolymer resin is greatly improved due to R3 and R4 on the cycloolefin monomer, and is first broken through to above 1.70, while maintaining high light transmittance of 91.0-96.0%, extremely low water absorption (<0.01%), and a glass transition temperature of 219 DEG C. The application prepares the cycloolefin copolymer resin with high activity, adjustable molecular weight and glass transition temperature by adjusting the reaction conditions. The copolymer resin has high refractive index, high light transmittance, heat resistance, low birefringence and moisture absorption, excellent fluidity, moldability and dimensional stability.

The invention belongs to the field of high-performance polymers, and relates to an olefin copolymer elastomer and a preparation method thereof. The olefin copolymer elastomer contains an ethylene structural unit, a propylene structural unit, a structural unit derived from cycloolefin and a structural unit derived from norbornene containing exocyclic double bonds; the cycloolefin is selected from at least one of compounds as shown in a formula 1; the norbornene containing exocyclic double bonds is selected from at least one of compounds shown in a formula 2 and a formula 3; in the formula 1 # imgabs0 #, a is an integer from 0 to 10; r < 1 > to R < 12 > are respectively and independently selected from hydrogen, alkyl groups of C < 1 > to C < 20 > or naphthenic groups of C < 4 > to C < 20 >; in the formula 2 and the formula 3, b is an integer of 0-10; and R < 13 > to R < 19 > are respectively and independently hydrogen or alkyl with 1 to 20 carbon atoms. The olefin copolymer elastomer disclosed by the invention has the properties of high light transmittance, high refractive index, excellent mechanical properties, excellent elasticity and the like.

This invention discloses a polymer coating material and its preparation method, as well as its application in artificial graphite anode materials. The polymer is synthesized from monomers, comonomers, and reaction auxiliaries under the action of an initiator. By controlling the amount of reaction auxiliaries added, the molecular weight of the polymer is controllable, and the side functional groups are adjustable. This polymer can uniformly coat the surface of artificial graphite, forming an artificial solid-state electrolyte interface, optimizing the lithium-ion transport path, and constructing a stable protective layer for the artificial graphite anode material. It can effectively improve the initial coulombic efficiency of the artificial graphite anode material, achieving an initial coulombic efficiency ≥91.8%.

The invention provides a polyphenylene ether polyol terminated with an alcohol hydroxyl group and a preparation method thereof. The polyphenylene ether polyol terminated with an alcohol hydroxyl group is prepared by reacting a double-terminated hydroxyl polyphenylene ether with an alkyl carbonate or an epoxide in the presence of an alkaline catalyst, and has alcohol hydroxyl groups at both ends. The molecular weight and degree of polymerization of the polyphenylene ether polyol terminated with an alcohol hydroxyl group are adjustable, and the property is stable. The polyphenylene ether polyol terminated with an alcohol hydroxyl group can be used not only to modify a polymer, but also as an intermediate for preparing a polymer. The addition of the polyphenylene ether polyol terminated with an alcohol hydroxyl group can give the obtained product some unique characteristics of polyphenylene ether, and improve the hardness, heat resistance and other properties of the obtained polymer. At the same time, the preparation method of the polyphenylene ether polyol terminated with an alcohol hydroxyl group is simple, the reaction selectivity is high, the yield is high, the production cost is low, and the application prospect is good.

The present invention provides a method for depolymerizing lignin, depolymerization products and applications, and relates to the field of green utilization of agricultural and forestry waste resources. The present invention adopts a new dual-functional solvent system with the ability to dissolve and degrade lignin, and realizes controllable and efficient depolymerization of industrial lignin. Under suitable depolymerization parameters, industrial lignin raw materials with a molecular weight of 10,000 to 200,000 and a molecular weight distribution of 2 to 5 can be degraded into oligomers with a molecular weight of 400 to 1200 and a molecular weight distribution of 1.2 to 2.0, the yield of the oligomers is 80 to 96%, and the hydroxyl value of the oligomers is 400 to 700 mgKOH / g. The comprehensive performance of the bio-based rigid foam polyurethane prepared from the raw materials is significantly better than that of similar petroleum-based products, and has excellent degradability and cost advantages.

The invention provides a self-healing and recyclable single-component joint filling adhesive and a preparation method thereof, and belongs to the technical field of organic polymer adhesives. The adhesive is prepared from the following components in parts by weight: 5.0 to 10.0 parts of epoxy resin, 7.0 to 20.0 parts of polyurethane modified epoxy resin, 5.0 to 10.0 parts of blocked isocyanate, 3.0 to 5.0 parts of hydrazide, 5.0 to 15.0 parts of liquid rubber, 2.0 to 5.0 parts of thixotropic agent and 30.0 to 50.0 parts of pigment filler. At room temperature, hydrazide and an epoxy group have chemical inertness, blocked isocyanate (which is unblocked by being heated to 130 DEG C) does not react with amino of hydrazide, and single-component packaging can be realized; the isocyanate group and reactive hydrogen atoms in hydrazide are subjected to an addition reaction to generate an acyl semicarbazide bond, and a large number of multiple hydrogen bonds can be formed between the acyl semicarbazide bond and a urethane bond, so that the single-component joint sealant is endowed with good self-healing and recycling performance.

The invention relates to the technical field of petroleum materials, and discloses a modified aminopolysiloxane polymer, a preparation method and an application thereof. The modified aminopolysiloxane polymer comprises the following steps: step 1: adding methoxy polyethylene glycol acrylate to a maleic anhydride solution under an inert gas atmosphere, adding an initiator, fully reacting, and purifying to obtain a maleic anhydride and methoxy polyethylene glycol acrylate copolymer; step 2: adding a catalyst to the copolymer solution obtained in step 1 under an inert gas atmosphere, dripping an aminopolysiloxane solution, fully reacting, and purifying to obtain a desired modified aminopolysiloxane polymer; the modified aminopolysiloxane polymer obtained by the invention can also form a spatial network structure under the cooperation of an auxiliary agent, so as to achieve the purpose of increasing the viscosity of supercritical carbon dioxide, and does not contain fluorine compounds in the preparation process, and avoids conventional precious metal catalysts and hazardous chemicals.

According to the preparation and application method of the functional oligomer based on oxidative cracking of the decommissioned polyolefin, oxidative cracking is carried out on a decommissioned polyolefin material through an organic catalytic system, and certain valuable oxygen-containing functional groups such as carboxyl and carbonyl are introduced into a cracking product while chain scission of the polymer is carried out, so that the decommissioned polyolefin material is obtained. The molecular weight, molecular weight distribution and oxidation functionality of the cracking product can be adjusted to obtain the functionalized oligomer, the functionalized oligomer can be used as a crystal hard phase, and a dynamic cross-linking reaction can be carried out on the functionalized oligomer and amorphous epoxidized rubber by virtue of the reaction activity of introduced oxygen-containing groups, so that an elastomer material with excellent performance is constructed. The method effectively solves the problems of high energy consumption, difficulty in product separation and subsequent utilization and the like in retired polyolefin recovery, realizes high-value upgrading recovery of retired polyolefin, and promotes green sustainable development of polymers and polymer engineering.

The invention discloses a method for recycling waste photovoltaic backboard polyester through click-dynamic crosslinking upgrading, and particularly relates to the field of new energy photovoltaic module recycling. The method comprises the following steps: crushing a PET polyester plate separated from a waste photovoltaic backboard, mixing the crushed PET polyester plate with dihydric alcohol and a catalyst, and heating to carry out glycolysis reaction so as to realize partial degradation and hydroxyl end capping of PET. A curing process is carried out by utilizing a reaction of carbon-carbon double bonds introduced in a repolymerization process and a dynamic cross-linking agent, and the prepared regenerated polyester product has excellent mechanical properties and excellent reprocessing properties. According to the method, no waste is generated in the polymerization process, the reaction is green and efficient, the performance of the product is close to that of commercially available PET plastic, the product is easy to reprocess, the product can be quickly healed at the temperature of 80 DEG C for 15 minutes after cracks appear, the product can be reprocessed into sheets at the temperature of 100 DEG C for 2 hours after being ground into powder, the recycling energy consumption is greatly reduced, and the commercial polyester material is expected to be partially replaced.

The invention relates to the technical field of petroleum materials, and discloses a modified amino polysiloxane polymer as well as a preparation method and application thereof, and the preparation method comprises the following steps: step 1, in an inert gas atmosphere, adding methoxy polyethylene glycol acrylate into a maleic anhydride solution, adding an initiator, and fully reacting to obtain a modified amino polysiloxane polymer; purifying to obtain a maleic anhydride and methoxy polyethylene glycol acrylate copolymer; and step 2, adding a catalyst into the copolymer solution obtained in the step 1 in an inert gas atmosphere, dropwise adding an amino polysiloxane solution, fully reacting, and purifying to obtain the required modified amino polysiloxane polymer, the modified amino polysiloxane polymer obtained by the invention can also form a spatial network structure under the synergy of auxiliaries, the purpose of improving the viscosity of supercritical carbon dioxide is achieved, fluorine compounds are not contained in the preparation process, and conventional noble metal catalysts and hazardous chemicals are avoided.